The invention relates to a turbine wheel meter for measuring a volume of a flowing medium, with a meter housing having a lateral opening, being penetrated by a duct having a discontinuity in a zone of the lateral opening, and with a tubular measuring insert disposed in the discontinuity and comprising an impeller and a reversing gear, as well as a flow regulator, arranged on the inlet side in the duct, upstream of the measuring insert, and being in the shape of a displacement member seated in a cylinder sleeve and provided with guide ribs, with a housing lid sealing the opening and carrying a counting mechanism on the outside.
The invention is utilized, in particular, with turbine wheel meters for gas supply systems wherein pipe diameters of four inches and more are used, and large volumes are to be measured at high pressures with great accuracy.
Turbine wheel meters with a straight flow channel have been proposed wherein surrounded by the flow of the medium a measuring insert, with an impeller, is arranged, with a flow regulator being disposed forwardly of the measuring insert. In a number of these meters, such as, for example, the type proposed in DOS No. 2,702,319 the flow divider or regulator and the measuring insert are placed into the flow channel in the longitudinal direction; however, a disadvantage of this arrangement resides in the fact that the turbine wheel meter must be removed from the length of conduit when exchanging those parts due to damage or for maintenance purposes, thereby resulting in a time consuming assembly work which is also rather cumbersome due to the considerable weight of the meter intended for large nominal cross sections.
In, for example, DOS No. 2,066,055, another turbine wheel meter is proposed which includes a meter housing having a lateral access to the flow channel through which the measuring insert with the impeller is introduced; however, a disadvantage of this proposed arrangement resides in the fact that an assembly of the flow divider or regulator takes place by insertion from the front into the flow channel. Consequently, for exchanging a damaged flow regulator, the entire meter housing must be removed from the conduit.
The aim underlying the present invention essentially resides in providing a turbine wheel meter constructed so that not only a measuring insert thereof but also the flow regulator can be removed from the meter housing without disassembly of the entire meter thereby enabling a calibration of the turbine wheel meter and flow regulator outside of the meter housing.
In accordance with advantageous features of the present invention, a turbine wheel meter of the aforementioned type is proposed wherein a length of a cylindrical sleeve of the turbine wheel meter is smaller than an inside diameter of a discontinuity or interruption of a duct of the meter, and the cylindrical sleeve of the flow regulator and measuring insert include plug-in and centering means having neutrally opposed end faces. The duct includes a cylindrical flaring portion emanating from the discontinuity or interruption, with a shoulder, the radial bearing surface of which, extends toward the discontinuity, and the cylindrical sleeve of the flow regulator seated in the flaring portion abuts, with a counter shoulder, the aforementioned shoulder. A circular ring-shaped clamping element is disposed between the measuring insert and the edge of the duct discontinuity or interruption on the discharge side.
By virtue of the above noted features of the present invention, it is possible to remove the measuring insert as well as the flow regulator from the lateral opening of the meter housing in the proposed turbine wheel meter without having to disassemble the entire meter from the length of the conduit. As can readily be appreciated, this means not only a simple assembly at the manufacturing plant but also a ready exchange of these essential components without any problems.
The plug in and centering means proposed by the present invention for releasably joining the two components makes it possible to calibrate or recalibrate the entire measuring device of the meter outside of the meter housing and insert the same only after completion of the calibration operation thereby saving expenses in manufacturing and servicing of the turbine wheel meter.
Advantageously, an end web having the shape of a circular ring which engages into the measuring insert is provided as the plug-in and centering means at the cylinder sleeve. This simple arrangement reliably ensures the position of the measuring insert and the flow regulator with respect to each other inside and outside of the meter housing.
A circular-ring-shaped end groove wherein a sealing ring is seated is suitably located beside the end web. This feature effects sealing of the junction point between the measuring insert and the flow regulator.
According to another feature of the invention, guide means for the measuring insert are provided in the meter housing in the zone of the duct discontinuity, with the guide means imparting to the measuring insert its prescribed location in the radial direction within the duct, and facilitating insertion and removal, respectively, of the flow regulator into and out of the duct.
Suitably, transverse ribs integrally formed in the interior of the meter housing serve as the guide means.
It is advantageous to fashion the clamping element to be spring-elastic. This clamping element, which thus can be utilized under tension, ensures the correct position of the measuring insert and the flow regulator in the axial direction.
The clamping element can carry along its edge a projecting fishplate as well as at least one tang attached at a right angle, with the fishplate facilitating the pulling out of the clamping element, and the aiding in attaching the element either to the meter housing or to the measuring insert.